Indicator and recorder for high pressure



Oct. 28, 1924.

A. BAHNMAYER INDICATOR AND RECORDER FOR HIGH PRESSURE Filed Feb.

Inventor Patented Oct. 28, 1924.

Peht'tih'? @FFECE.

ARTHUR BAHNMAYER, GE FANN GERMANY.

INDICATOR AND RECORDER IIEGE Appflication filed February 528 .7 '0 aZZwhom it may concern:

Be it known that I, ARTHUR BAHNMAYER, a citizen of the German Empire,residing at Mannheim, Germany, have invented certain new and usefulImprovements in Indicators and Recorders for High Pressure, of which thefollowing is a specification.

My invention relates to a novel and very advantageously constructedindicator for i high pressures, for the recording and measuring ofpressures in riveting, pressing and drawing operations. I

It is well known that presses, as rivetingmachines, drawing-presses,block-presses and the like, which are operated by press-fluid orpress-air frequently work in a way that the same working-pressureoperates upon active piston-faces (steps) of different sizes. Thiscauses operating pressures of different pow- 29 er on the work-piece oron the tool, e. g. on

the punch of a riveting-machine. A further variation or graduation ofthe operating pressures results from the variation of the tension or"the driving-medium, the latter may for instance be raised from n atmospheres to 2 'n atmospheres.

My invention has for its object an indicator which surely and positivelyoperates and indicates at the highest pressures happening in doing theaforementioned work without having the indicator submitted to anymaterial change in its ordinary construction and shape. Furthermore myinvention aims to simple means for automatically indicating suchoperative pressures to be used in the riveting-machines or the like asreliable and economical for the work at hand e. g.'the diameters of therivets or the scales of the sheet-metals.

In order to make myself quite clear to tacilitate the understanding ofmy invention I refer to the accompanying drawing, in

which the new device is shown as an instance only, partly in section,partly in plan view 5 together with a hydraulic riveting-machine and itsaccumulator, the two latter devices on an essentially smaller scale thanthe former.

hat is said and explained herein about rivetingmachines applies also toany other press-device, when a rational treatment or" the work-piece tobe dressed, the control of the proceeding and the workmen themselves aredesired.

In the drawing, C designates a rivetingmachine, which in this instanceworks with cation a twostepped piston I and II. It you cause theworking-medium (the operating water and so forth) to act upon bothpiston-steps you get a third step I I It the normal water-pressure inthis instance amounts to n kilograms per square centimeter thecompression of three different grades can be exercised on the die 0 Z ofthe riveting-machine 0.

As shown in the drawings the pump A acts by means of the pressing tubesin the well known way on the accumulator B. The accumulator B feeds inthe likewise well known way by means of the tubes 3 and 4 therivetingunachine C. According to the rivet diameter either step I orstep II, or both steps together as step III, will be operated.

There are tubes 64 and 5 leading from the compressionspaces I and IIrespectively of the rivetin unachine C to an indicator D, the feature ofwhich is its being constructed as a differential indicator. The rivetingmachine provided with two valves 27 and 28; for throwing into operationthe step I the valve 28 is shut off and the valve 2? opened, for settinginto operation the step II valve 27 is closed and valve 28 opened. Thestep III comes into operation by opening both the valves 27 and The samepressure which is acting upon the different steps comes into operationwithin the corresponding tubes and spaces which are in communiwith theircorresponding steps. Eve y time when a step 01 the riveting-machinereceives a pressure the water-pressur also operates at the same time onthe two dillerential pistons and 70 The two pistons k and k are fixed toa piston-rod consisting of two parts 7c", 7J5 articulated by a hinge Thestroke of the differential pistons if, 70 is marked on the drum G by thewriting-lever f. The areas or" these two indicator pistons are such thata comparatively small differential pressure is produced in an upwarddirection, as the piston of the larger area is toward the upper end ofthe indicator cylinder 3, thus allowing the oper ation of the writinglever f by the usual lever-arrangement 5, 6 and an indicator spring Fhaving the usual or normal resilient force, ZiQVGlillQlQSS the highestpressures are upheld within the riveting-machine.

It is a further feature of my invention to have the indicator drumadjusted in accordance with the step of the riveting machine just inoperation. For this purpose the drum Gris fastened to a piston rod 6carrying three adjusting pistons 1, 2, 3; these pistons rigidlyconnected to the rod 6 are of increas ing diameters and adapted'to slidewithin the corresponding driving cylinders (Z d and E. The cylinders (Zand E are in communication respectivelv with the steps II and I of themachine by tubes a and b.

At its upper end the drum G is in connection with a piston rod 1 towhich is fixed a counter-piston H, sliding within a cylinder 7L1 incommunication by 4: with the accumulator B.

The drum G comprises three recording sections in accordance with thethree operative steps I, II and III of the riveting machine, the firstsection extending between the zero-line and the 50 tons-line, the secondsection between the 50 tons-line and the 100 tons-line, whereas thethird section lies between the 100 tons-line and the 150 tons-line. Asthe writing-lever 7 extends over one section of the drum G only, thelatter has to be adjusted in such a way, that if the step I of themachine is' in operation the writing pencil of the lever f is standingupon the zero-line. Owing to the fact that the tribe Z) is shut off bythe piston 3 and the cylinder his fed with pressure fluid thecounter-p1ston H is enabled to hold the drum G in its uppermost positionas shown by the drawing. If the step I of the machine is shut off andthe step II is fed with pressure fluid, the latter flows by the tube ainto the cylinder d and forces the rod 6 together with the drum Gdownwardly; of course it is understood that thewater also passes betweenthe upper face of the piston 2 and the shoulder 03"; the downwardmovement is cut oil if the piston 1 closes the tube a; in this case the50 tons-line coincides with the pencil of the writing lever f Shouldthere be fed both the steps I and II with pressure water, the latterflows by the tube 6 into the cylinder E, containing the largest pistonand accordingly throws the drum G into its lowest position, whereby thepencil of the writing lever automatically coincides with the 100tons-line. 7'

A further important feature'of my inven I tion forms the means toautomatically control the work when done and to prevent the work-piecefrom receiving unreliable working pressures. For this the followingarrangement is provided: a stopping arm a, carrying an insulated contactpiece 8, 1s movably mounted on a guiding rod by means of a sleeve L; tothe latter is attached a rack 11, which engages with pinions 12, 13; onthe axis 14C of the latter is keyed a cam wheel I: having in accordancewith the three steps of the riveting machine three teeth 16 of differentlength and adapted to cooperate with corresponding teeth 17 of arotatable sector 7, having a pointer 19, to be adjusted on a.

graduated are 20, and a curved arm 79 adap ed to cooperate with a fixedstop wall 21 thus forming a controlling j aw of changeable widthintended to receive the rivets to be the three steps I, II, III.According to the diameter of the controlling rivet 22 the said jaw willassume a corresponding width and therefore the sector J performs arotative motion, which is transmitted by means of the points 16, 17, thepinions 13, 12 to the rack 11 whereby the stopping arm a is lifted tothe prescribed height; as in the drawing the pointer 19 points to theend of the first section-scale of the graduated are 23 the stopping armcoincides with the tons-line of the drum G. Should there be produced ahigher pressure by the riveting. machine, the contact 25 of the writinglever strikes on the contact 8 whereby a current is closed over abattery 26 to an alarm bell f which sounds and gives a signal to theworkman. To obtain the second step the corresponding teeth 17 and 16must disengage from each other,

thus permitting of the cam wheel K and the gearwheels 13 and 12 acorresponding backward rotation till the following points 16. 17 engagewith each other. Due to this backward movement the stopping arm 0; isal-- lowed to descend on its initial position; a tension spring 26supports the downward movement of the arm a Now the control ling j awZ), 21 is adapted to receive a larger rivet.

I'Iaving now particularly described and ascertained the nature of mysaid invention and inwhat manner the same is to'be performed, I declarethat what I claim is:

1; An arrangement for recording and measuring high pressures inriveting, pressingand drawing works, comprising in combinationdifferential pistons A operated by the working-fluid,diii'erential-cylinders receiving the said difie'rential pistons, apiston rod carrying the said differential pistons, a writing-leveroperated by the said piston rod, an indicator spring preferably of theusual structure, influencing the writinglever, a writing-drum adapted tobe movedin axial direction and cooperating with the said Writing lever,an adjusting rod and adjusting pistons thereon of difierent diametersfor carrying the said drum, governing cylinders, receiving the saidadjusting pistons and fluid conducting tubes for bringing intocommunication the differential-cylinders and the governing-cylinderswith the working-machine substantially as described.

2. In the arrangement for recording and measuring highpressures a devicefor indicating and controlling the fluid-pressure as required,comprising a movable arm and a stop-wall, forming a jaw of changeablewidth, a rotatable sector carrying said movable arm, a pointer anddriving organs arranged at said sector, gearing wheels cooperating withthe said sector-organs, .La stopping arm slidably mounted and adapted tobe operated by the said gear wheels and carrying an electrical contact,a writing lever, cooperating with the said stopping arm and contact atcertain positions and means for producing a signal in case the writinglever and stopping arm interfere with each other, substantially asdescribed.

3. In the arrangement for recording and measuring high pressures inriveting and the like machines, an indicator comprising a plurality ofdifferential pistons, a corresponding number of differential cylinders,receiving the said differential pistons, piston rod-sections carryingthe corresponding dilierential pistons and being articulated with eachother, fluid pressure tubes putting into communication the pressurespaces of the riveting and the like machine with the dili erentialcylinders, a writing lever, -a lever-arrangement for guiding the writinglever, an indicator spring preferably of the usual art, cooperating withthe writing lever and an adjustable drum for carrying the indicatorstrip substantially as described.

l. In the arrangement for recording and measuring high pressures incombination ith a pressure source and a machine for riveting and thelike, a movable drum, an adjusting-rod to which the said drum isfastened, diiierential adjusting pistons, drivcylinders for receivingthe said differierential adjusting pistons, fluid tubes putting intocommunication the machine and the pressure source with the said drivingcylinders, the adjusting pistons being adapted to shut oil single tubesat certain positions of the adjusting pistons and the drum respectively.

5. In the arrangement for recording and measuring high pressures inriveting and the like machines, comprising in combination adiagram-strip, a carrier for the latter, differential adjusting pistonsand driving cylinders for the adjustment of the said strip-carrier,means for conducting the pressure-fluid from the working machine to thesaid adjusting cylinders, a controlling jaw of changeable width adaptedto cooperate with the working-piece as a rivet and the like, a movablestopping arm and a writinglever cooperating for producing a signal incase the prescribed working pressure is surpassed and means fortransmitting the move ment of the movable jaw to the stopping arm.

6. In the indicator arrangement as herein before described, avcontrolling jaw consisting of a movable and a fixed part and adapted tobe adjusted in accordance with the scale of the working-piece (rivet,sheet or the like) to be dressed, a pointer in connection with themovable part of the controlling jaw, to show the working pressureas'reliable for the work to be done, a stopping arm cooperating with thewriting lever of the indicator and a transmitting gear for trans mittingthe movement of the said movable part of the jaw to the said stoppingarm.

7. In the indicator-arrangement as herein before described, acontrolling jaw comprising a movable and a fixed part and adapted toreceive the working-piece (rivet, sheet or the like) to be dressed, astopping arm cooperating with the writing-organ of the indicator, meansfor transmitting the movement of the movable part of the controlling jawto the stopping arm, and a signaling device alarming the workman, if theoper ative fluid pressure is surpassed, by the cooperation of thestopping arm with the writing lever.

In testimony whereof I aflix my signature in presence of two witnesses.

DR. ARTHUR BAHNMAYER.

W'itnesses.

ARTHUR Scrmonnnn, J OHN M. BULKLEY. l

